1. Field of the Invention
The present invention relates to organic light emitting elements and a manufacturing method of the same, organic display panels, and organic display devices.
2. Description of Related Art
In recent years, progress has been made in the research and development of organic electroluminescent elements (hereinafter, “organic EL elements”), which are light-emitting elements that rely on the phenomenon of electroluminescence of organic material. The structure of an organic EL panel that uses conventional organic EL elements is described with reference to FIG. 9.
As shown in FIG. 9, a thin-film transistor layer (hereinafter, “TFT layer”) 901, passivation film 902, and planarizing film 903 are layered in this order above a substrate 900 in the organic EL panel. The TFT layer 901 is composed of a gate electrode 9011, drain electrode 9012, source electrode 9013, channel layer 9014, and gate insulation film 9015.
In this organic EL panel, an anode 905 and auxiliary electrode 906 are provided, with a space therebetween, along the surface of the planarizing film 903, and on each anode 905 and auxiliary electrode 906, a hole-injection layer 913 and a hole-injection layer 914 are respectively laminated. The portion of this organic EL panel in which the anode 905 is formed corresponds to a light emitting cell 90a, and the portion in which the auxiliary electrode 906 is formed corresponds to a non-light emitting portion 90b. Banks 907 are formed between light emitting cells 90a, as well as between a light emitting cell 90a and a non-light emitting portion 90b. 
In the light emitting cell 90a in the organic EL panel, an interlayer 908, organic light emitting layer 909, electron transport layer 910, and cathode 911 are laminated in this order in a region defined by the banks 907. The electron transport layer 910 is formed continuously across adjacent light emitting cells 90a and non-light emitting portions 90b, passing over the banks 907, as is also the case with the cathode 911. In the non-light emitting portion 90b, the cathode 911 is connected to the auxiliary electrode 906 through the hole-injection layer 914 and electron transport layer 910 (the portion indicated by arrow C).
The cathode 911 in this organic EL panel is covered by a passivation layer 912.
Note that instead of using silver (Ag), a conventional material for forming the anode 905 and the auxiliary electrode 906, development and research is proceeding regarding the use of a metal alloy that includes aluminum, a less expensive metal.
Furthermore, technology to prevent intrusion of water or oxygen (Patent Literature 1) by using a non-crystalline transparent conductive film has been suggested, as has technology to form an oxide layer on the surface of the anode, via a technique such as electrolytic plating, and to have the oxide layer contact with the organic light emitting layer in order to achieve high luminous efficiency (Patent Literature 2).
It has also been suggested to use a metal oxide, such as a transition metal oxide, to form the hole-injection layers 913 and 914 (Patent Literature 3, 4). Hole-injection layers 913 and 914 formed with such a material have the advantages of excellent voltage-current density characteristics and of not deteriorating easily even when a high current flows to increase emission intensity.
3. Related Literature
Patent Literature 1: Japanese Patent Application Publication No. 2007-149703
Patent Literature 2: Japanese Patent Application Publication No. 2002-203687
Patent Literature 3: Japanese Patent Application Publication No. 2007-288071
Patent Literature 4: Japanese Patent Application Publication No. 2005-203339